The overall goal of this Phase II project is to develop, test, and commercialize glutamate biosensors that can be used to measure cytotoxic concentrations of glutamate under low oxygen conditions (pO2< 40 torr). Specific aims of this proposal include: complete development and testing of 180 urn-diameter glutamate biosensors for low oxygen environments and 76 um-diameter for normal oxygen environments and manufacture for sale; develop and test a 76 um-diameter, low pO2 glutamate biosensor; develop a software-configurable, 2-channel, head-mounted, wireless potentiostat that can perform the simultaneous measurement of oxygen and glutamate under ischemic conditions, in freely moving rats; introduce automation at key points in the manufacturing process and investigate electrodeposition techniques to increase sensor manufacturing yield and facilitate the development of smaller sensors. To reach these objectives Pinnacle Technology and the University of Kansas are building on past successes in the design of glutamate biosensors and wireless potentiostats for rats. These products were developed in separate collaborations and are currently being commercialized. Products to be introduced as a result of this Phase II proposal include a 76 urn glutamate biosensor and 180 urn glutamate biosensor for use under ischemic conditions, a 76 um glutamate sensor for use under normal pO2 conditions, and the wireless potentiostat system. Commercial applications include stroke research, disease research and drug discovery. Technological innovations include biosensor, and biosensor membrane design, turnkey head mount design, and advanced electronics design. Each year about 700,000 people in the United States have a stroke, over 80 percent of which are ischemic. An excess of glutamate is believed to be responsible for much of the damage done to brain cells during cerebral ischemia events (stroke), but the interdependent physiological processes surrounding glutamate release/transport/uptake during ischemia are poorly understood. In order to study these events, a new system needed to be developed which would measure glutamate under the ischemic, low oxygen conditions [unreadable] [unreadable]